CRISPR-mediated gene correction links the ATP7A M1311V mutations with amyotrophic lateral sclerosis pathogenesis in one individual

Abstract

Amyotrophic lateral sclerosis (ALS) is a severe disease causing motor neuron death, but a complete cure has not been developed and related genes have not been defined in more than 80% of cases. Here we compared whole genome sequencing results from a male ALS patient and his healthy parents to identify relevant variants, and chose one variant in the X-linked ATP7A gene, M1311V, as a strong disease-linked candidate after profound examination. Although this variant is not rare in the Ashkenazi Jewish population according to results in the genome aggregation database (gnomAD), CRISPR-mediated gene correction of this mutation in patient-derived and re-differentiated motor neurons drastically rescued neuronal activities and functions. These results suggest that the ATP7A M1311V mutation has a potential responsibility for ALS in this patient and might be a potential therapeutic target, revealed here by a personalized medicine strategy.

The M1311V variant of ATP7A is associated with impaired trafficking and copper homeostasis in models of motor neuron disease

“…1B , C and S1A ). Consistent with increased reactive oxygen species previously described in neural progenitor cells ( Yun et al, 2020 ), we observed a significantly decreased ratio of reduced to oxidized glutathione (GSH/GSSG) in fibroblasts carrying the M1311V mutation compared to two control lines, reflecting an inherent increased state of intracellular oxidative stress ( Fig. S1B ).…”

“…A variant of ATP7A, ATP7A M1311V has recently been identified in a patient with brachial amyotrophic diplegia/flail arm syndrome (also called man-in-barrel syndrome) with slow-progressing ALS ( Yun et al, 2020 ). ALS is a neurodegenerative disease characterized by loss of motor neurons in the brain, brainstem and spinal cord, along with muscle atrophy ( Al-Chalabi et al, 2012 ).…”

“…Patient-derived induced pluripotent stem cells (iPSC) carrying ATP7A M1311V differentiated into motor neurons showed elevated levels of reactive oxygen species and cell damage markers (lactate dehydrogenase) as well as decreased firing action potential compared to controls. These phenotypes could be rescued with CRISPR-mediated correction of the variant, thus linking the variant to impaired motor neuron function and potentially neurodegeneration ( Yun et al, 2020 ).…”

CRISPR and iPSCs: Recent Developments and Future Perspectives in Neurodegenerative Disease Modelling, Research, and Therapeutics

“…The combination of whole-genome sequencing-based gene variant discovery and CRISPR-iPSC-based disease modelling techniques has accelerated the discovery of rare yet highly penetrant ALS-causing novel gene variants which only certain ethnic groups are predisposed to (Yun et al 2020 ). A sizeable fraction of the published studies have reported the utilization of CRISPR/Cas9-corrected patient-derived iPSC lines to generate isogenic disease models.…”

Stem Cell Models and Gene Targeting for Human Motor Neuron Diseases

“…A recent study based on whole-genome sequencing identified one demographic variant in the X-linked ATP7A gene, M1311V as a strong candidate in pathogenesis. They corrected this mutation using CRISPR-Cas9 in iPSCs-derived from the patient's fibroblasts and demonstrated significant restoration of the neuronal defects in these corrected iPSC-derived motor neurons [85]. It has been reported recently that, human motor neurons with CRISPR-Cas9 generated SOD1-G93A mutation showed disease-relevant phenotypes including SOD1 aggregation, axonal degeneration, and aberrant synaptic functions [86].…”